ESP8266 Community Forum

Pablo2048 wrote:Why you don't search for the answer by yourself? BTW even TCP connection has keepalive mechanism...

Or better yet, do a real test and see what the data is, rather than accept what someone wrote on the Internet.

Use Wireshark to see what the transfers are.

stern0m1 wrote:Is there a service that you can send data to the esp8266 over the internet without port forwarding and without constantly polling some server?
Thanks

Let's try download firmware Sputnik.bin http://bortx.ru/firmware/sputnik.bin
Load this bin to esp8266 from 0 address by nodemcu flasher etc. More on http://bortx.ru
If some problem - i'll help

You access to your esp directly through your router without port-forwarding when you use IPv6.

It's not really ipv6 that avoids port forwarding.

Port forwarding is the technique used by routers that employ NAT (pretty much all home routers) to allow devices behind the NAT to be addressed by using specific ports.

You can turn off NAT on a router providing you have proper internet ip addresses for all your devices. This applies whether it is ipv4 or ipv6. The difference is just that it is not really viable to get internet wide ip4 addresses any more.

Normally the goal of this question is to get a means to access to home devices for users without them having to change router settings. In that context using ipv6 is no better and probably worse than using port forwarding.

Assuming NAT is in use, I think there are only 3 basic techniques to communicate with an internal device from outside.

1) Port forwarding
2) Device polls a service for any outstanding requests
3) Device requests a connection with a service that is then kept open to allow inbound messaging.